5 Red Days In A Row: Amgen Stock Is Down 15%
A sharp, multi-day slide in Amgen stock has put its price in contrast with its underlying business metrics.
A five-day slide in Amgen (AMGN) stock has erased about $36 billion from the company’s market value. The stock has now moved lower for 5 consecutive trading days, a cumulative loss of 15%. That leaves the company’s market value standing at about $204 billion.
For anyone holding the shares, the recent move is a sharp reversal. The stock’s performance over the last month now sits in negative territory, even as its even as its broader trailing returns remain firmly positive.
The Streak Next To The S&P 500
Here is how AMGN stock stacks up against the S&P 500 over the streak and the periods around it:
| Return Period | AMGN | S&P 500 |
|---|---|---|
| 1D | -1.3% | 0.9% |
| 5D (Current Streak) | -15.0% | -1.2% |
| 1M (21D) | -8.8% | -1.2% |
| 3M (63D) | 7.2% | 3.6% |
| YTD 2026 | 17.6% | 11.9% |
| 2025 | 29.7% | 16.4% |
| 2024 | -6.8% | 23.3% |
| 2023 | 13.5% | 24.2% |
A pipeline setback weighs on a sturdy core business
The 15% decline is largely specific to Amgen; over the same 5 trading days, the S&P 500 returned -1.2%. While the streak is not unique, with 45 other S&P 500 stocks on losing streaks of 5 days or more, its magnitude stands out.
While standard trading data does not show why market participants sold across this five-day window, the sharp decline followed clinical trial fallout in the Lp(a) cardiovascular space. On September 4, Novartis reported that its Phase 3 Lp(a)HORIZON study evaluating pelacarsen failed to meet its primary cardiovascular endpoint. That setback cast doubt over the commercial and clinical viability of Amgen’s competing Phase 3 candidate, olpasiran, triggering a direct spillover selloff in AMGN shares.
Viewed purely as business context rather than an explanation for the streak, Amgen’s reported trailing fundamentals remain sturdy: revenue over the last twelve months grew 9.1%, ahead of the S&P 500 median of 8.3%, and its 3-year average annual revenue growth is 12.8%. Its operating margin of 30.0% is also well above the index median of 18.6%. Despite this, the stock trades at a price-to-earnings multiple of 23.3, below the median of 25.1 for its Health Care sector peers. The company also has a free cash flow yield of 5.0%.
A streak is a signal to check the thesis, not change it.
A string of losses like this one is information. It tells you where market momentum and attention are focused, but it is not an instruction to act. The stock’s longer-term returns show this move in a different light; despite the recent slide, Amgen has returned +7.2% over the trailing three months and +39.2% over the trailing twelve months.
The disciplined response is to compare the new price to the underlying business. The data on growth, profitability, and valuation provide a starting point for that assessment.
A slide like this poses an obvious follow-up: which marked-down stocks are actually worth buying? Our Buy the Dip screen runs that test every day, flagging beaten-down names whose fundamentals still hold up.
Those watching the group rather than this one name have another route: a biotech ETF like IBB holds the industry, not the single stock. It is still a concentrated bet on that one theme, though, which is exactly the gap the portfolio below closes.
Falling Prices Test Conviction. Rules Do Not Flinch
A losing streak forces a choice on every holder: sell into weakness, average down, or freeze. All three are emotional answers to what should be an analytical question, and decisions made that way tend to be expensive ones.
The Trefis High Quality (HQ) Portfolio takes the emotion out: about 30 quality businesses screened for the fundamentals that survive bad stretches, held and rebalanced by rules. It has a track record of outpacing a benchmark that combines the three major indices – the S&P 500, S&P Mid-cap, and Russell 2000. Let the rules decide, not the tape.